What does a joint capsule primarily do?

The primary role of a joint capsule is to provide stability to the joint. Joint capsules surround and encase the joint, creating a protective layer that helps to maintain the alignment of the bones at the joint interface. This stability is crucial for the joint to function effectively, as it prevents excessive movement that could lead to injuries, such as dislocations. Furthermore, the joint capsule contains synovial fluid, which aids in lubricating the joint and reducing friction during movement, thereby supporting both stability and mobility. Understanding this role can help recognize how injuries or diseases affecting the joint capsule can impact overall joint function and health.